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55% Mini Racer, Weekender ? Need your inpouts

#1
55% Mini Racer, Weekender like ? Need your inputs

Hi there, name is Guy, i get to planes thanks to FliteTest crew.
A friend of mine came to the field last day with a mini plane from Hitec, the ZIPPER. Plane was awesome and i was thinking... Maybe... Maybe... Maybe having David's Racer scaled down to 55% will do...
So i did scale down the plane and i ended up with this: IMG_2006.jpg
I decided to get rid of the rudder for this build.
This is a 30 cm = 12 inches next to the plane, so you can have an idea of the size. For my gears, i used:
-5g servos from HK
-Turnigy 10A plush ESC from HK
-3mm plywood for the motor mount
-Gift card for control horns
-Futaba 4 ch FASST micro receiver for my 10CG (I had to to mix AIL and RUD to get the AILERONS working, using the rudder channel as a AIL left)
-APC 4.1*4.1 propeller from Tower Hobby
-2s 500 mA Zippy battery from HK
And for the motor (my mistake a think)
-Turnigy 2204-14T...

A bunch of pics for you:
IMG_2006.jpg IMG_2015.jpg IMG_2014.jpg IMG_2012.jpg IMG_2011.jpg IMG_2010.jpg IMG_2009.jpg IMG_2008.jpg IMG_2007.jpg IMG_2016.jpg

Yes, i had to add some weight to get the CG on the spot.

The total weight of this bird is 198g in working order with this settings.

I have to maiden it before i glue the front deck but i feel like the motor is too weak and it is too windy to maiden today.

I think i would buy the Eflight park 180 2400 kv that use the same ESC as i already have, i spotted it on the web for 30 box or so.

I would appreciate your thoughts about that.

I am an average builder but i am helpless with the motor. I think i correctly choose the prop and ESC so my focus got to the motor, but feel free to comment the bundle BATTERY-ESC-MOTOR-PROP

David and Josh, if you have any thoughts, about downsizing your designs please let me know.

Thanks for your help.

Guy.
 
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Ron B

Posted a thousand or more times
#2
If it does feel under powered with the 2 cell then try a 3 cell if motor will take a 3 cell. I know nothing about this motor but just thinking.
 

rcspaceflight

creator of virtual planes
#3
I agree with Ron B. I have some 500mah Zippy 3S batteries and they don't weigh very much. You'd get an increase in power without much weight gain.
 
#4
Alright, i dug more since my last post, on that subject. The thing is at the end, to know how to choose the proper motor, propeller, esc and battery set for your model, witch is a very interesting subject to go with.

I just saw 2 videos of the Joshs:
-1st is about watt-meters
-the other one is about trust

As a scratch builder, i definitly need a watt meter to check my power systems, this is going to be my next purchase.
Turns out after some research that all units are not trusty, some of them can be off...

The HK-10 seems to do the trick.
http://www.youtube.com/watch?v=ire7S810Gu4

The Turnigy 130 watt meter is off so i will avoid it.
Gt Power Rc LCD 130a High Precision Watt Meter and Power Analyzer might be a good deal, it is as the Turnigy 130 watt meter but the readings a right on this one.

See the following video:

http://www.youtube.com/watch?v=Lxv9Rozs774

Very interesting...

Do you guys have any advice for a good quality piece of equipment ?
 
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rcspaceflight

creator of virtual planes
#5
I think when people say that a watt meter is off, it's usually about 5-10% off. Which is still accurate enough to tell you what you need to know. Plus, watt meters are generally used to find the most efficient prop for a motor. So as long as you're using the same watt meter, any watt meter would work because hopefully it would be off by the same 5-10% each reading. Even if you're checking for tolerances and want to make sure you're not drawing more amps than your ESC can handle, it's still fine if it's a bit off. The "80% rule" is a great rule to follow. You should only be using 80% of what any electronic is rated at. So if you have a 20amp ESC, you should only run 16amps through it to ensure that it lasts as long as possible.

Point is, don't over think it. Electronic guys tend to be picky about tolerances and error rates.

I looked on Hobby King's site at the motor you have and it recommends an 8x4 prop if you're using a 2S battery. Even though that doesn't go along with the racer look, it might be worth going with the bigger prop to give the prop more air to grab on to which will get the plane to speed faster. But not a faster speed. You might have to watch out for torque roll.

Your current setup with an 8x4 prop might be worth a try. Maybe even try it as is before you start ordering new parts.




The plane looks great and I hope you get it working.
 
#6
Yes i think rcspaceflight might be right on this one:

No need to get crazy about this watt-meter thing but i think there is certainly a need to get a watt-meter to control gears at full burst so you will be sure to not burn something over your 5-10 min flight, just don't need to be obsessed.

In my case, i bought the motor with its recommended ESC and battery, but i went for a 4.1*4.1 prop instead of the 8.4 recommended due to the scale.
I don't know how is this setting is going to react at full throttle during all the time flight on 2s and worst on 3s (motor and ESC can handle 3s on paper).
Watt-meter can help you only with gears you already have, because you can't test things you don't have in front of you.

Point is, for new gear buyers, the manufacturers have to provide full characteristics witch tend to be the case now, but sometimes they do not provide enough information (you see this on HK reviews from time to time, people are asking for full motor characteristics).

Concerning the trust of my actual setting: Admitting my actual setup can handle the amp passing through my gears at full throttle on 2s, when i hand the plane at full throttle, i feel like a small lack of power. So i am sure that it will do at 3s as suggested by you too (thanks for your help). I just need to be sure this is not going to fire up the whole plane ;-) = Watt-meter

I did order the HK-10 in USA warehouse. we have a rainy day here so the maiden will have to wait anyway...

I also have followed your advises and went for 2*zippy 3s 500 mA in the same order - even if my actual gears can't handle 3s with the 4.1*4.1 prop, it will not hurt me to have them in my battery collections for other projects.

I can't try a 8*4 prop on this plane because the plane is way to small for this prop !!! i think this would give me way too much tork and would concourse for ugliness ;-) A 8*4 prop represent close to half of the total size of the plane !!

I really want to have this project going on so i glue everything and go for airbrushing ;-)

I'll then need to have a new post maybe to present my actual finished Spit, Racer, Ripslinger ;-) all airbrushed or this finished project.

Thanks for the compliment on the built rcspaceflight.

If i do good with this project, i'll post a video of the maiden for sure. And this will be thanks to your help.

NB: sorry for my English - i am french so my English is faulty.
 
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Freaky_1

old headcase
#7
Guy, no apologies necessary, your english is fine.

I'm of no use on your concerns as I'm new to EP and my knowledge is useless.
I would like to compliment you on your build though. Me thinks you'll have one zippy litle beauty there when you get your power sorted out. Cant wait to see it roar!

Have a blessed day and thanks for sharing,
Frank
 
#9
Are you using the 5mm foam or did you go thinner?
I am thinking of doing scale-down to but with 3mm foamboard.
I've done a scaled down Spitfire (only 80% size nothing as small as this) and used 3mm foam and worked really well, 5mm would be too heavy/bulky for this i reckon
 
#10
I went for 60% on my swappable builds as it's perfect for the 3mm Depron I use.

My 2S powerpod (288g thrust) has:
hexTronik 20gram Brushless Outrunner 2300kv
TURNIGY Plush 10amp 9gram Speed Controller
ZIPPY Compact 500mAh 2S 25C Lipo Pack
APC Style Propeller 6x4 (2pc)

My 3S powerpod (436g thrust) has:
Turnigy Aerodrive SK3 - 2122-2100kv Brushless Outrunner Motor
TURNIGY Plush 12amp (2A BEC) BESC
ZIPPY Compact 500mAh 3S 25C Lipo Pack
APC Style Propeller 6x4 (2pc)

The 3S powerpod has enough thrust to propel my 188g MiG-7 at over 92km/h (measured using HK's doppler app). I tried the Plush 10A, but it just didn't give enough top end.

I'm not really keen on the APC style props for Turnigy motors, I had to use some heat shrink tube glued to one of the sizing rings to get a tight fit. I'm trying out the Turnigy Sport (TGS Sport 6x4E Precision propeller) next.

I hope this helps in some form or another Guy.

Cheers!
Randall
 
#11
Are you using the 5mm foam or did you go thinner?
I am thinking of doing scale-down to but with 3mm foamboard.

Hello Tophe75, yes i did use exactly the same $tree foam board for this project.

I scaled down to 55% for particular reasons though:

-I wanted a "weekender size", witch is pretty small
-I wanted the 5gr servos to fit as good as the 9gr servos in the wings = they did: they have been sandwiched between the upper and lower part of the wing tightly.
-I wanted all spar holes to accept natively (after the shrinking process) the width of one sheet of $Tree board (4mm).

Benefit of this built:

The shrinking process contribute to a tremendous amount of rigidity for the whole thing !!! i think this is going to be able to handle L O T of crashes. Much more than a regular plane bought in the market.

For information, they are actually priced within 99$ and 150$ for this size.

So far, i have something like:

1$ foam board.
3*2$ servos
around 18$ for the motor and ESC
7$ battery
...

If i get the right gears and if this is flying. This could be fantastic to play with !! for less than 50box !!

I hope that help.

Guy
 
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#12
Guy, no apologies necessary, your english is fine.

I'm of no use on your concerns as I'm new to EP and my knowledge is useless.
I would like to compliment you on your build though. Me thinks you'll have one zippy litle beauty there when you get your power sorted out. Cant wait to see it roar!

Have a blessed day and thanks for sharing,
Frank
Hello Freaky_1 Thank you for your support, i appreciate it ;-) As i just scaled down the plane and remove the rudder, i have no clues if this is going to work as good as the the original.
Maybe shrinking things this much changes the behavior of the whole thing.

This is going to be a surprise, but i will at least know and let you guys know what is going on.

Best and Bless. Guy
 
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#13
I've done a scaled down Spitfire (only 80% size nothing as small as this) and used 3mm foam and worked really well, 5mm would be too heavy/bulky for this i reckon
Hello ENOS, if you have a mini SpitFire (80% down) i must have a micro racer ;-)

But let's not get too happy. Actually yours has maiden witch is not my case ;-)

If it does not work for me as it is, i will follow your path and rebuild one at 55% scale but with 3mm foam so the power system will have more latitude to express itself.

Guy
 
#14
I went for 60% on my swappable builds as it's perfect for the 3mm Depron I use.

My 2S powerpod (288g thrust) has:
hexTronik 20gram Brushless Outrunner 2300kv
TURNIGY Plush 10amp 9gram Speed Controller
ZIPPY Compact 500mAh 2S 25C Lipo Pack
APC Style Propeller 6x4 (2pc)

My 3S powerpod (436g thrust) has:
Turnigy Aerodrive SK3 - 2122-2100kv Brushless Outrunner Motor
TURNIGY Plush 12amp (2A BEC) BESC
ZIPPY Compact 500mAh 3S 25C Lipo Pack
APC Style Propeller 6x4 (2pc)

The 3S powerpod has enough thrust to propel my 188g MiG-7 at over 92km/h (measured using HK's doppler app). I tried the Plush 10A, but it just didn't give enough top end.

I'm not really keen on the APC style props for Turnigy motors, I had to use some heat shrink tube glued to one of the sizing rings to get a tight fit. I'm trying out the Turnigy Sport (TGS Sport 6x4E Precision propeller) next.

I hope this helps in some form or another Guy.

Cheers!
Randall
Hi Randall_l, thank you for your input.

Can you tell me where you did get your 3mm depron ?
Just in case my built end up too heavy for the power system ;-)

For the motor, i was thinking of ordering the Eflight park 180 2400kv motor witch has the same characteristics as the motor furnished by HITEC with their ZIPPER. I am glad you just confirmed that would have been a good move.

Maybe i will order it just to test. And maybe a hextronik 20gr out runner 2300kv also, just to check if the difference of the price on those two is justified...

For the ESC i ordered the 10A turnigy plush, i think i will go for the 12A if this build is successful (I then will build a micro Spit for sure ;-))

Do you have any videos of your two settings working with those props ?

Best and Bless.

Guy
 
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#15
My local hobby shop had a bunch, but I bought the last of it and they won't be getting any more. They got it from rcfoam.com, which is where I will make my next order from.

I haven't received the Turnigy Sport props yet.

I'm afraid I'm the only one in my village that flies, so finding camera persons is a bit difficult. I do have a fairly bad video of the MiG 7 with a 2S battery on my YouTube channel (http://www.youtube.com/watch?v=pYQr0YL8PYI). This spring, I hope to get my hat mounted camera tuned so it's usable. It'd be nice to share some of my fun.

Cheers!
Randall
 
#16
My local hobby shop had a bunch, but I bought the last of it and they won't be getting any more. They got it from rcfoam.com, which is where I will make my next order from.

I haven't received the Turnigy Sport props yet.

I'm afraid I'm the only one in my village that flies, so finding camera persons is a bit difficult. I do have a fairly bad video of the MiG 7 with a 2S battery on my YouTube channel (http://www.youtube.com/watch?v=pYQr0YL8PYI). This spring, I hope to get my hat mounted camera tuned so it's usable. It'd be nice to share some of my fun.

Cheers!
Randall

Hello Randall

I checked you video on YouTube, you did good ;-) i wish you had some closer footages of the plane itself but you did good.

This is a powerful system you have there !!!

I hope more people will get involved in your area, i myself try to get people in this hobby and at this same moment i am helping a friend to scratch built a design.

Best&Bless.

Guy
 
#17
Aw heck. The "reply to thread" got me again (much more attention grabbing than the "Post Quick Reply" button).

I had quite a bit of difficulty flying inside the box that my iPhone provided. It's such a fast plane even on 2S and with flaperons as down as I dared.

I've got one prospective student, but I think they're going to wait until spring. I've made the offer and I've been reading up on the MAAC training exercises. I got a wireless buddy box unit in my Christmas stocking so I've built another 2S pod for it--just have to plug in another receiver and go.

Cheers!
Randall
 
#18
Aw heck. The "reply to thread" got me again (much more attention grabbing than the "Post Quick Reply" button).

I had quite a bit of difficulty flying inside the box that my iPhone provided. It's such a fast plane even on 2S and with flaperons as down as I dared.

I've got one prospective student, but I think they're going to wait until spring. I've made the offer and I've been reading up on the MAAC training exercises. I got a wireless buddy box unit in my Christmas stocking so I've built another 2S pod for it--just have to plug in another receiver and go.

Cheers!
Randall
Same here,

The weather is so bad i can't get my fingers on my radio for more than 10 min, as i am in a test phase of this project, this is not easy.

I wish you the best for this summer anyways.

Guy

NB: Do you by any chance live in France ?
 
#19
Allright !!

I was waiting for my orders to come in so i can update this thread.

I did receive my HK-010 (watt meter tester) and i am very happy with it as it comes with built in balancer, Lipo tester also for the most interesting parts.
I also received my zippy 3s Lipo 500mA
And i received the Eflight parc 180

Here are the facts:

I verified that at full throttle, the Turnigy 2204-14T with 4.1*4.1 prop was under the Amp spec of the ESC and motor:
Here are the results:
On 2S, full throttle gave me
-2 Amps and 18 watts drained
On 3S, full throttle gave me
-3.2 Amps and 35.6 watts drained

OR

Max current on the 2204-14 is 7.5 Amp if i believe HK www, and burst current on the ESC is 12 A so if i understand correctly, i am WAY under the limits of those components.

I then tried to fly on 3s - (Turnigy 2204-14T/4.1*4.1 APC prop/Plush 10A): Power was much better than on 2s but i think this is still not enough. Plane was going down every time even when throwing in front of the wind.

I tested the Eflight parc 180 and i hooked it up with the turnigy plush 10A this morning instead of the Turnigy 2204-14T i still have.

IMG_2022.jpg IMG_2023.jpg

As you can see on 2S at full throttle i got 1.8A and 14.8 watts drained, on 3s 2.7 A and 31.5 watts with same propeller and same ESC

Eflight Park 180 Motor spec says it is ok up to 30watts so it is just on 3s... though I think it would handle it because o the good ventilation an because i assume the manufacturer does allow itself some range on that parameter.

With this new configuration, I still feel there is not enough power to fly properly in fact i feel the parc 180 even less powerful...

I may have to go for a 6.4 prop instead of my 4.1*4.1 - what are your thoughts about that ?
Also, i wonder if i do not have to add more surface for ailerons and elevator as actually those surfaces are very small...

I am a bit discouraged actually because i can't get this thing in the air and i did spent some dollars. I might have bought undersized motors/propeller/ESC for this project.

I am still willing to go on to find the right power system. For the gears i already have, i might need to find other projects like indoor flights.

Thanks in advance for your help.

Guy
 
#20
The ailerons look about right for the size of the wing. The faster it flies, the less control movement is needed.

HobbyKing recommends an 8040 or 7035 for the 2204-14T, so a 6x4 may be a little small for 2S. On the other hand, it'll certainly help keep the current draw down on 3S.

It sounds like you're going through a similar learning curve to me. I did a lot of research, ordered a bunch of stuff and it's still sitting in my parts bins today.

Don't get discouraged. The lessons I've learned along the way were well worth the extra hardware in the end--and I'll find a home for it at some point. The whole community here is very helpful and encouraging, so if I can't help you there will be someone else who can.

With that said, what can I do to help?

Sorry friend--not even on the same continent. I live in Ashcroft, BC Canada.

I recently extended my cold-weather flying down to -15C. I ordered the Turnigy Transmitter Glove and HobbyKing Universal Heater system. It works great on the 2S 2200mAh batteries I have, but only lasts about 15 minutes before the low voltage alarm I place on the balance lead goes off. It's enough time to walk to or from work (I usually fly one of my Old Fogey's to/from work). It has however, been windy enough to ground me this past week. I'm starting to make headway on other projects, so it's been a good thing.

Cheers!
Randall